1. Field of the Invention
The motorcycle fork extension of the present invention relates to a method and apparatus for extending the travel of a motorcycle fork to thus smooth out the ride and enable such motorcycle to accommodate rough terrain without loss of control by the driver.
2. Description of the Prior Art
Motorcycle forks are commonly formed with downwardly opening hollow tines having upwardly opening hollow sliders received thereover with a damper rod secured on its lower extremity to the slider also received telescopically within the tines. The damper rods are commonly biased downwardly within the tines and the up rate and down rate of the slider and tine relative to one another is commonly controlled by orifices formed in the wall of the damper rod to control oil flow past a sealing ring mounted in the lower extremity of such tine and telescopically receiving the hollow damper rod.
While motorcycle forks of this general type are generally acceptable for operation over relatively smooth surfaces such as highways and freeways, the off-road operation of such motorcycles is more demanding and requires considerably more shock absorption to accommodate the rougher terrain without loss of control. For instance, when the conventional motorcycle forks encounter rugged terrain at high rates of speed, resulting in such forks bottoming out, there is a tendency for the handlebars to twist in one direction or the other and for the rider to be pitched over the handlebars.
Efforts to modify such conventional motorcycle forks have led to the addition of overload or helper springs for resisting shock. However, such proposed solutions have been unsatisfactory because they stiffen the suspension system and reduce the absorption rate of such forks and, further, frequently require dampening oil having a relatively high viscosity in order to adequately resist damper rod travel.